Point to multi point services exist today which allow data from a single source entity to be transmitted to multiple end points. These services are expected to be used extensively over wireless networks. In particular there is a strong interest to provide multimedia broadcast/multicast service over 3G networks.
The multimedia broadcast/multicast service (MBMS) which is considered for the universal mobile telecommunications systems (UMTS) is a unidirectional point-to-multi point bearer service in which data is transmitted from a single source entity to multiple recipients. 3GPP has defined two modes of operation: (i) the broadcast mode and (ii) the multicast mode.
The broadcast mode is a unidirectional point-to-multi point transmission of multimedia data from a single source entity to all users in a broadcast area or areas. Data is transmitted to broadcast areas as defined by the network. A broadcast service received by a user equipment involves one or more successive broadcast sessions. A broadcast service might, for example, consist of a single on-going session, e.g. a media stream, or may involve several intermittent sessions over an extended period of time, e.g. messages. An example of a service using the broadcast mode could be advertising or a welcome message to the network. As not all users attached to the network may wish to receive these messages then the user shall be able to enable/disable the reception of these broadcast services on his user equipment. A disadvantage of the broadcast mode is that power control cannot be performed individually for the user equipment.
The multicast mode enables the unidirectional point-to-multi point transmission of multimedia data from a single source point to a multicast group in a multicast area. Like in the broadcast mode data is transmitted to multicast areas as defined by the network. In the multicast mode there is the possibility for the network to selectively transmit to cells within the multicast area which contain members of a multicast group. Such multicast services allow unidirectional point-to-multi point transmission of multimedia data, e.g. text, audio, picture, video, from a single source point to a multicast group in a multicast area. An example of a service using the multicast mode could be an information service for which a subscription is required, e.g. a football results service for which a subscription is required.
In the multicast mode data is streamed in parallel from the radio network controller to the node-B for transmission to the user equipment. For further technical information on the multimedia broadcast/multicast service (MBMS) reference is made to ETSI TS 122 146 V5.2.0(2002-03) and 3GPP TS 25.346 V1.3.0(2003-01) the entirety of which is herein incorporated by reference.
Broadcast and multicast services for other digital wireless communication networks, such as digital TV, DVD-T and DVB-M are also considered in “Broadcast and Multicast Services in Mobile Networks, Ahmavaara K., Jolma P. and Raivio Y.”
(http://www.nokia.com/downloads/aboutnokia/research/library/mobile_networks/MNW9.pdf)